Orthorhombic to tetragonal phase transition in Y1Ba2Cu3O7−x

Abstract
Quenching experiments were performed to study the orthorhombic to tetragonal phase transition in Y1Ba2Cu3O7−x. The quenched and unquenched specimens were characterized by x‐ray diffraction and optical microscopy. The phase transition temperature was found to be dependent on the environment of the sealed specimens during quenching, and could be as high as 1173 K (900 °C). The phase transition is suggested to be of second order.